Troll

The troll regains 5 hit points whenever it starts its turn and has at least 1 hit point. When the troll takes fire or acid damage, its regeneration does not function on its next turn.

Troll Healing (healing)

Whenever an attack that doesn’t deal acid or fire damage reduces the troll to 0 hit points, the troll does not die and instead falls unconscious until the start of its next turn, when it returns to life with 15 hit points. If an attack hits the troll and deals any acid or fire damage while the troll is unconscious, it does not return to life in this way.

Standard Actions Claw At-Will

Attack: Melee 2 (one creature); +14 vs. AC

Hit: 3d6 + 7 damage. If the attack bloodies the target, the troll uses claw against it again.